Brown-headed Cowbird (Molothrus ater) Science Article 15
I studied patterns of cowbird parasitism and responses to this parasitism by Bell’s Vireos (Vireo bellii) in Kansas. Bell’s Vireos abandoned parasitized nests at a significantly higher rate than unparasitized nests. Lower probability of brood parasitism later in the season may help make abandonment followed by renesting beneficial.
TIMOTHY H. PARKER, Wilson Bull., 11 l(4), 1999, pp. 499-504